Improvement in method of increasing capacity of oil-wells



Witnesses, A Mm Inventor.

UNITED STATES ,PATENT Oi-TICE.

EDWARD A. L. ROBERTS, OF NEV YORK.

IMPROVEMENT IN METHOD OF lNCREASlNG CAPACITY OF OIL-WELLS.

Letters Patent No. 69,936, dated November 20, 1866 antedated May 20, 1866.

' SPECIFICATICN.

To all whom it may concern: L

Be it known that I, EDWARD A. L. Iton- ERTS, of the city, county, and State of New York, have invented a new and useful Method of Increasing the Capacity of- Oil-Wells, andlof restoring oil-wells that have become clogged to productiveness; and I hereby declare that the following is a full and correct description thereof, reference beinghad to the accompanying drawings and the letters of reference marked hereon making a part of this speciication, a portion of which represents the apparatus used by me in working out my said invention. l

The petroleum or oil taken from the oilwells is, before it is removed, contained in seams,usually in the second or third stratums of sandstone, or, other rock abounding in the oil regions, which are represented in Fig. 1 of the accompanying drawings.

Figure l represents a sectional view of the different stratums of rock usually found in oil-producing regions, and the seams or crevices containing the oil are represented by the irregular lines traversing the second and third stratums of sandstone rock there shown. n and n represent wells sunk4 into the rocks.

In order to take the oil from the seams or crevices in the rock, wells must be sunk which shall tap or intersect the seams,or some of them, containing the oil.- The wells are frequently sunk to the depth of from eight hun dred to nine hundred feet below the surface of the earth, andusually from three to six inches in diameter, and it frequentlyhappens a well will be sunk for a great distance into or through the rock containing the oil without tapping or passing through any of the sea-ms in which it is contained, as shown by r the course of the well n in Fig. 1. When.

this happens to be the case, the well is sometimes -made available by 'increasing its diam, eter until it strikes some ofthe seams; this is done by boring from the top all the way down into the stratum of rock containing the oil, and is attended with nearly as much labor and expense as boring the well in the first 'instance. 1t also-frequently happens that the seam intersected by the4 well is very small, or that the aperture into the well from the seam' is very small, in either of which cases 'itis It is desirable, in

very liable to become clogged or stopped up, during the workin g of the well, by substances contained therein,-which prevents the oil from ilowin g or being sucked into the well. These stoppages are removed sometimes by enlarging the diameter ofthe well, as before stated, and sometimes, when the diiiculty is slight, by 'forcing air down to or near the bottom of the well and allowing it suddenly to escape.

order to increase the productiveness of wells, as well as to prevent stoppages from obstructions, to have the well tap or connect with as many of the seams or crevices of the rock containing the oil as pos! sible. The capacity of wells, structed, to tap or intersect seams is lim'ited by the circumference ofy the well.

In my improved method of increasing the capacity of wells, I fracture the rock containing the oil to some distance around the wells, thus creating artificial seams, and enabling me to connect the well thereby with seams containing the oil that ,would not have been otherwise reached by the well, and also to enlargethe aperture into any seam that might have been tapped by the well, and this I accomplishes follows: in the usual manner to a suticieut depth, I sink a flask containin g gunpowder or other powerful explosive material or gas down the well until it reaches the bottom of the well or that portion of it which passes throughthe oil-bearing rock. When the flask has reached this position, if the well. above should not be lled with water when the flask islet down, (which will almost always be the case unless it has been pumped out )it is then to be lled up before the contents o the ask are ignited; the column of water then above the ask will be of so great gravity as to confine the effect of the explosion to the rock in the immediate vicinity of the ilask, without materially aiecting the stratums of `rock above, and I make ,use of it;for that purpose. I then ignite the contents of' the ilask by means of fulminatingpowder, electricity, or other means used to ex. plode shells, torpedoes, or cartridges under water, and the explosion which thereupon takes place fractures the oil bearing rock, opens the seams therein, and connects them with the wells; and when the seams leading as at present coninto awell have become stopped by substances When the well is bored` a canse getting into the seams and closing it so as to prevent the oil from flowing or being sucked into the well, as before described, such stoppages may be removed more readily' by the aid of an explosion produced in the vicinity of the stoppage than can be done by any means now in use.

In order more fully to explain my method of working, I will describe the apparatus I use.

Fig. 2 represents a sectional view of the hollow flask, made of iron, or glass, orother material, and lled with powder or other explosive materials, with the cover and` means of letting the same down into the well and exploding the contents.

Letter a is the body of the ask containing the powder or explosive materials. b is a cover screwing down on the top of the flask, water-tight, and covers the hole through which the powder is introduced. lugs, placed at or near the top of the flask, and on opposite sides of the cover, into which cords are fastened to assist in letting the ask down into the well and in removing it, if for any reason the contents should not explode. c is a stuihng-boxor gland, through which the wire d passes, which connects at one end with a small quantity of fulminating-powder upon the disks e and e on that end of the wire in the interior of the flask, and at the other end with a cord extending ont of the top ot' the well, and sufficiently strong to enable the operator to pull the wire d, through the stuing-box c, with sufficient force to ignite.v the fulminating-powder on the disks e e', on'the end of the wire d, which will readily ignite the powder in the flask a. If electricity is used to ignite the contents of the iiask the wires can vpass through the stuffing-box. c in the same manner as the wire d, or the contents of the iiask may b e ignited by means of the arrangement shown at Fig. 3, in which a represents the iiask. g and g are percussion-caps tting up`- on the top of the hollow nipples h and h on the top of the flask, connecting with the powder on the inside, and placed nearA together on opposite sides and equidistant from the wire z', which is connected Iwith the top ol' the iask in any manner convenient, and isused to assist in letting the flask down into or in raising it out ofthe well, and also to guide the weight lw ixrits descent to the caps on the nipples. zb is an oblong weight, madel of any metal of l l are two smallv sufficient gravity to fall rapidly throughrgthe largeenough to allow wire t' to pass easily through it where the iiask is in position. The contents may beexploded by allowing the weight to slide down the wire to the caps, which will be exploded by the concussion, and the contents of the iiask thereby ignited. After the caps are put on the nipples they should be varnished, or other similar substance applied to them, to make the connection betweeuthem impervious to water. u

In Fig. 3 the ask has no cover, but the powder is introduced through a hole in thebottom, which is stopped by the screw-plug p, which is made to fit water-tight.

I prefer to have the iiask made of cast-iron or glass. It should be suiciently strong to resist the pressure of the column of water 'which will be above it when sunk to the requiredvdeth, and made impervious to moist ure. It should be alittle less in diameter than the diameter of the bore of the well, in order to slide easily down the bore of the well through the water.

The length of the ask will depend upon the amount of force which may be required for the explosion, care being taken not to have it so great as .to shatter or displace the y sides of the well above the rock which it is desired to have opened by the explosion, to guard against which the flask should be somewhat shorter than the distance which the well extends into the oilfbearing rock.

Instead 6f the particular means above described by me for igniting the contents of the flask, any means used to explode shells, torpedos, or cartridges under water may be employed for that purpose.

What I claim as my invention, and desire to secure by Letters Patent, is-

The above-described method of increasing the productiveness of oil-wells by causing an explosion of .gunpowder or its equivalent, substant-ially as above described.

' E. A. L. ROBERTS.

Witnesses:

ERAs'rUs Trrns, Jr., MARCUS SAcKE'rT. 

